Relationships between Aerosol and Raindrop Size Distributions during Rainfall Period (Changma) in Jeju Island, Korea

Abstract

To investigate the variation in aerosol particles removed by rainfall, we determined the relationship between aerosols and raindrops observed on Jeju Island, Korea, during a heavy rainfall period (Changma) from 1–15 July 2012. Various instruments, including an aerodynamic particle sizer, rain gauge, and disdrometer, were installed at the Gosan meteorological observation site on Jeju Island. During the Changma period, precipitation between 0.7 and 25.4 mm per day was recorded, and large variations in aerosol and raindrop size distributions were observed. Aerosol removal by precipitation was indicated, and its scavenging effect was confirmed from the results. Three major parameters (Brownian diffusion, interception, and impaction) described the collision efficiency based on aerosol and raindrop size distributions. The variations in the scavenging coefficient and below-cloud scavenging rate produced similar results for the accumulated rain amount. Therefore, these field observations explained the relationship between aerosol and raindrop size distributions.